When an Australian man named Terry gave his girlfriend, Anna, a one-of-a-kind wooden necklace in celebration of their one-year anniversary, Anna assumed the pendant had little monetary value. It was only after wearing the odd piece for a full 18 months that she learned the truth.

As reported by the Daily Mail, Terry, who declined to provide his last name, crafted the simple wooden necklace, made of Tasmanian pine and featuring a shell as decoration, as an anniversary gift for his girlfriend, Anna. After receiving the necklace, Anna wore it nearly every day, including during activities like grocery shopping and passing through airport security.

What Anna didn’t know was that the necklace featured a secret compartment and, within that hidden space, was an engagement ring.

Anna wore the necklace for a full 18-months before she and Terry went on a trip to Scotland to visit ‘Smoo Cave,’ a destination that was on both of their bucket lists.

Upon arriving at the cave, Terry requested the necklace from Anna, saying he wanted “to take some photos of it among the rocks.” He used the time to break the seal that kept the two halves of the necklace together, revealing the ring inside. Then, he set up his camera to capture the moment.

“I took the necklace from my pocket, kneeled, broke it open and revealed that something was hidden inside the entire time,” said Terry.

While speaking to the Daily Mail, Terry admitted, “I had always loved the idea of giving someone a gift where they didn’t know its true value.”

Anna quickly said “yes” but followed that response with the statement, “But I could have lost it, you f***ing idiot!”

Terry did state that he experienced a “moment of panic” when Anna crossed through airport security with the necklace for the first time. “I hadn’t thought about the fact that she might be asked to put it through the x-ray, which could have quickly turned into an airport security proposal.”

He also said that he was surprised by the reaction to the video he uploaded showing the proposal. “We didn’t realize how crazy this was going to get when we uploaded the video – we figured it was more for family and friends to tell them about it.”